body {
  background-color: #abdde8;
  text-align: center;
  overflow: hidden;
  margin: 0;
  /* padding: 0; */
}

.switch {
  background-color: white;
  width: 400px;
  height: 140px;
  position: absolute;
  left: 50%;
  margin-left: -200px;
  top: 65%;
  border-radius: 8px;
}

/* 切换按钮 */
#change:checked+label,
/* +用来选择同级后面最近的元素 */
#change:not(:checked)+label {
  background-color: #FFB8CE;
  color: white;
  width: 280px;
  padding: 8px 0;
  /* 用padding方便文字垂直居中 */
  font-size: 24px;
  font-weight: 600;
  position: absolute;
  left: 50%;
  margin-left: -140px;
  top: 72%;
  border-radius: 8px;
  cursor: pointer;
}

/* 旋转体 */
.turn {
  width: 400px;
  height: 400px;
  position: absolute;
  left: 50%;
  margin-left: -200px;
  top: 8%;
  perspective: 800px;
  /* 旋转的时候透视效果 */
}

.over {
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: all 1.6s ease;
  /* 旋转持续时间 */
  /* ease逐落慢下来 */
}


#change:checked~.turn .over {
  transform: rotateY(180deg);
}

form {
  top: 40%;
  position: absolute;
  background-color: #fcfbfa;
  height: 100%;
  border-radius: 8px;
  transform-style: preserve-3d;
}

.sign {
  transform: rotateY(180deg);
}

h1,
h2 {
  color: #1f2029;
  user-select: none;
}

h1 {
  margin-top: 38px;
  transform-style: preserve-3d;
  transform: translate3d(0, 0, 1px);
}

input {
  background-color: #4E495D;
  width: 70%;
  height: 48px;
  border-radius: 8px;
  margin-bottom: 20px;
  padding: 0 16px;
  font-size: 18px;
  color: white;
  font-weight: 500;
  outline: none;
  border: none;
  box-shadow: 0 4px 8px 0 rgba(78, 73, 79, .5);
  transform-style: preserve-3d;
  transform: translate3d(0, 0, 1px);
}

input::placeholder {
  color: gainsboro;
}

.login input:nth-child(-n+3) {
  /* 选择class为login的子元素中的前三个input */
  margin: 20px 0;
}

.btn {
  background-color: #981E61;
  border: none;
  width: 280px;
  font-size: 24px;
  font-weight: 600;
  color: white;
  padding: 6px 0;
  border-radius: 8px;
  margin-top: 15px;
}